Poweradmin account takeover via OIDC subject collation bypass

Severity: high · CVSS 8.1 · Published 2026-07-24

Poweradmin, a web-based control panel for DNS management, contains a flaw in how it handles external logins via OpenID Connect (OIDC). An attacker who can create an account on the same login provider can use a specially crafted username (using similar-looking characters) to trick the system into logging them into a victim's account. This allows the attacker to gain full control over the victim's DNS settings and personal data without knowing their password.

Technologies: Poweradmin. Vendors: Poweradmin.

Quick answers

Is This vulnerability exploited in the wild?
No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?
High severity, with a CVSS score of 8.1, published 24 July 2026.
Which products and versions are affected?
Poweradmin >= 4.1.0, < 4.2.5; >= 4.3.0, < 4.3.4.
Is there a fix for This vulnerability?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is This vulnerability attacked?
It is attacked over the network, in a network appliance.
Am I affected?
Check whether you run Poweradmin at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

Poweradmin maps OIDC/SAML identities to local users using the `oidc_user_links` table. The `oidc_subject` column uses the `utf8mb4_unicode_ci` MySQL collation, which is accent-insensitive (e.g., 'i' equals 'í'). When an attacker authenticates with a subject identifier that is an accent variant of an existing user, the SQL lookup `WHERE oidc_subject = ?` matches the victim's record. The application then assigns the victim's `user_id` to the attacker's session. This allows full account takeover if the attacker can control their subject string at the Identity Provider (IdP). The issue is fixed in versions 4.2.5, 4.3.4, and 4.4.0 by migrating columns to binary collation and using byte-exact matching.

Affected products

  • Poweradmin Poweradmin >= 4.1.0, < 4.2.5; >= 4.3.0, < 4.3.4

Timeline

  • 2026-07-23: advisory: Initial GitHub Advisory published
  • 2026-07-24: disclosed: Full technical details and PoC released

References

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